Integrated circuit device performance in the sub 100 nm range is often limited by short-channel effects. Such short-channel effects make further scaling difficult if not impossible. These effects are usually manifested as a reduction in transconductance, an increase in output conductance and a shift in the threshold voltage as transistor gate length is reduced.
Another manifestation of short channel effects is an increase in the sub-threshold current. For low power or for high performance applications, tight control on the sub-threshold drain current and threshold voltage is needed. Challenges to the source-drain doping and requirement for scaled ultra shallow junctions which demand adequate doping abruptness with high doping activation, may be a major limiting barrier to technology development beyond the 65 nm range.